A bush may be fitted in a bore in a component to provide an inner surface within the bore. The inner surface may, for example, provide a bearing surface for receiving a rod or shaft which passes through or into the component. The bush may have a flange which locates the bush within the bore and covers the interface between the bush and the bore surface.
Over time, the performance of the bush may be reduced, for example due to degradation of the bush and/or the bore surface. Degradation of the interface between the bush and the bore may occur due to contamination, for example by water, oil, dirt or debris, resulting in surface corrosion of the bush and/or bore. The flange may act to reduce contamination of the interface between the bush and the bore, and a layer of sealant may be applied over the bush flange and the surface of the component to seal the bush. However, contamination/corrosion of the bush may still occur, particularly if the layer of sealant becomes damaged or degraded, for example due to mechanical wear, corrosion or age hardening.
In some cases, it may become necessary to replace the bush, or to re-bore the component and fit a new bush having a larger outside diameter to fit the new bore, or even to replace the component entirely if extensive corrosion has occurred. The problem of contamination of bushes may present a particular problem for large bush assemblies, in which the parts may be difficult and expensive to maintain, monitor and replace. If the component is an aircraft component, for example a main landing gear component, these maintenance tasks may require the aircraft to be removed from service while the maintenance tasks are carried out. Replacing a main landing gear component due to a degraded bush assembly may be time consuming, expensive and wasteful of materials.